how do you know what elements result from Gold 179 undergoing alpha decay?

Question

I need the balanced equation

Answer 1

Alpha decay means a helium nucleus is removed.

that is a compound is formed which has the atomic number which is 2 less than the gold
and atomic weight which is 4 less than gold

BALANCED EQUATION
GOLD179 (atomic no.=79)------->IRIDIUM175 (atomic no.=77) +helium nucleus

Answer 2

gold 179 has 79 protons and 100 neutrons

When a nuceus emits an alpha which has 2 protons and 2 neutrons ,it loses 2 protons and two neutrons

so after alpha emission, the nucleus remaining has 77 protons and 98 neutrons looking a periodic table you see that element with 77 protons is called irridium IR

you obtain IR 175